Liquid crystal display and manufacturing method thereof

ABSTRACT

A liquid crystal display is provided. The liquid crystal display includes a substrate including a reflective area and a transmissive area, a thin film transistor disposed on the substrate, a pixel electrode disposed on the thin film transistor, and a roof layer disposed facing the pixel electrode. The liquid crystal display further includes a plurality of microcavities formed between the pixel electrode and the roof layer, and a liquid crystal material disposed in the plurality of microcavities. The reflective area includes a first cell gap, and the transmissive area includes a second cell gap that is different from the first cell gap.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.14/261,181, filed on Apr. 24, 2014, which claims priority to and thebenefit of Korean Patent Application No. 10-2013-0126048 filed in theKorean Intellectual Property Office on Oct. 22, 2013, the entirecontents of which are incorporated herein by reference.

BACKGROUND

(a) Field

The present disclosure relates to a liquid crystal display and amanufacturing method thereof.

(b) Description of the Related Art

A liquid crystal display, which is one of the most common types of flatpanel displays currently in use, typically includes two sheets ofdisplay panels with field generating electrodes (such as a pixelelectrode and a common electrode) and a liquid crystal layer interposedtherebetween.

The liquid crystal display generates an electric field in the liquidcrystal layer by applying a voltage to the field generating electrodes.The electric field determines the alignment of liquid crystal moleculesin the liquid crystal layer, which controls polarization of incidentlight, thereby enabling images to be displayed.

The liquid crystal display can be manufactured using different methods.For example, a method of forming a pixel unit having a cavity andfilling a liquid crystal therein has been developed. Specifically, themethod may include forming a sacrificial layer (comprising an organicmaterial and the like) on a lower plate, removing the sacrificial layerafter forming a support member thereon, and filling a liquid crystal inthe empty space (formed by the removal of the sacrificial layer) througha liquid crystal injection hole.

Different types of liquid crystal display devices may possess differentdisplay characteristics. For example, a transmissive liquid crystaldisplay including a backlight may have high luminance and high contrastratio indoors (e.g. inside a building), but low luminance and lowcontrast ratio outdoors. On the other hand, a reflective liquid crystaldisplay may have good electro-optical characteristics outdoors (by usingnatural light from the surroundings as a light source), but poorelectro-optical characteristic indoors.

Accordingly, there is a need for a liquid crystal display combining theabove-described advantages of both the transmissive and reflectiveliquid crystal displays without having their inherent deficiencies.

SUMMARY

The present disclosure is directed to address at least the above need,by providing a double cell gap structure in a transflective liquidcrystal display using sacrificial layers of different thicknesses.

According to some embodiments of the inventive concept, a liquid crystaldisplay is provided. The liquid crystal display includes a substrateincluding a reflective area and a transmissive area; a thin filmtransistor disposed on the substrate; a pixel electrode disposed on thethin film transistor; and a roof layer disposed facing the pixelelectrode, wherein a plurality of microcavities are formed between thepixel electrode and the roof layer, and a liquid crystal material isdisposed in the plurality of microcavities, and wherein the reflectivearea includes a first cell gap, and the transmissive area includes asecond cell gap that is different from the first cell gap. In someembodiments, the first cell gap may correspond to a height of themicrocavities in the reflective area, and the second cell gap maycorrespond to a height of the microcavities in the transmissive area.

In some embodiments, the first cell gap may be smaller than the secondcell gap.

In some embodiments, a thickness of the roof layer in the reflectivearea may be different from a thickness of the roof layer in thetransmissive area.

In some embodiments, the pixel electrode may include a transparentelectrode and a reflective electrode disposed on a first portion of thetransparent electrode, and the first portion of the transparentelectrode and the reflective electrode may be disposed in the reflectivearea, and a second portion of the transparent electrode may be disposedin the transmissive area.

In some embodiments, each of the reflective area and the transmissivearea may correspond to one unit pixel area.

In some embodiments, the reflective area may include one of a pixel areaadjacent in a horizontal direction and a pixel area adjacent in avertical direction, and the transmissive area may include the other oneof the pixel area adjacent in the horizontal direction and the pixelarea adjacent in the vertical direction.

In some embodiments, the liquid crystal display may further include acommon electrode and a lower insulating layer disposed between themicrocavity and the roof layer, wherein the lower insulating layer maybe disposed on the common electrode.

In some embodiments, the liquid crystal display may further include acapping layer disposed on the roof layer, wherein a liquid crystalinjection hole formation region may be disposed between the plurality ofmicrocavities, and the capping layer may be disposed covering the liquidcrystal injection hole formation region. In some embodiments, the liquidcrystal injection hole formation region may extend in a directionparallel to a gate line connected to the thin film transistor.

According to some other embodiments of the inventive concept, a methodof manufacturing a liquid crystal display is provided. The methodincludes forming a thin film transistor on a substrate; forming a pixelelectrode, wherein the pixel electrode is connected to a terminal of thethin film transistor; forming a sacrificial layer on the pixelelectrode, wherein the sacrificial layer includes a first portion havinga first thickness and a second portion having a second thickness;forming a roof layer on the sacrificial layer; forming, by removing thesacrificial layer, a plurality of microcavities having a liquid crystalinjection hole; and injecting an alignment material and a liquid crystalmaterial into the plurality of microcavities through the liquid crystalinjection hole, wherein the first portion of the sacrificial layercorresponds to a reflective area, and the second portion of thesacrificial layer corresponds to a transmissive area.

In some embodiments, the first thickness may correspond to a cell gap ofthe reflective area, and the second thickness may correspond to a cellgap of the transmissive area.

In some embodiments, a thickness of the roof layer in the reflectivearea may be greater than a thickness of the roof layer in thetransmissive area.

In some embodiments, forming the sacrificial layer on the pixelelectrode may further include forming the first portion and the secondportion alternately in a direction of a gate line connected to the thinfilm transistor.

In some embodiments, forming the sacrificial layer on the pixelelectrode may further include forming the first portion and the secondportion alternately in a direction of a data line connected to the thinfilm transistor.

In some embodiments, the method may further include forming a commonelectrode and a lower insulating layer on the sacrificial layer beforeforming the roof layer.

In some embodiments, the method may further include forming a cappinglayer on the roof layer to cover the liquid crystal injection hole.

In some embodiments, a liquid crystal injection hole formation regionmay be formed between the plurality of microcavities, and the cappinglayer may be formed covering the liquid crystal injection hole formationregion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating a liquid crystal display according toan exemplary embodiment of the inventive concept.

FIG. 2 is a cross-sectional view of the liquid crystal display of FIG. 1taken along line II-II.

FIG. 3 is a cross-sectional view of the liquid crystal display of FIG. 1taken along line

FIG. 4 is a plan view schematically illustrating a reflective area and atransmissive area in the liquid crystal display of FIG. 1.

FIG. 5 is a plan view illustrating an exemplary embodiment in which thelayout of the reflective area and the transmissive area in FIG. 4 ismodified.

FIG. 6 is a plan view illustrating another exemplary embodiment in whichthe layout of the reflective area and the transmissive area in FIG. 4 ismodified.

FIGS. 7 to 17 are cross-sectional views illustrating a method ofmanufacturing a liquid crystal display according to an exemplaryembodiment of the inventive concept.

DETAILED DESCRIPTION

Exemplary embodiments of the inventive concept will be described indetail herein with reference to the accompanying drawings. As thoseskilled in the art would realize, the described embodiments may bemodified in various ways without departing from the spirit or scope ofthe inventive concept. In the drawings, the thickness of layers, films,panels, regions, etc., may be exaggerated for clarity. It will beunderstood that when a layer is referred to as being “on” another layeror substrate, it can be disposed directly on the other layer orsubstrate, or with one or more intervening layers or substrates beingpresent. Like reference numerals designate like elements throughout thespecification. FIG. 1 is a plan view illustrating a liquid crystaldisplay according to an exemplary embodiment of the inventive concept.FIG. 2 is a cross-sectional view of the liquid crystal display of FIG. 1taken along line II-II. FIG. 3 is a cross-sectional view of the liquidcrystal display of FIG. 1 taken along line FIG. 4 is a plan viewschematically illustrating a reflective area and a transmissive area inthe liquid crystal display of FIG. 1.

The liquid crystal display includes a plurality of pixels PX disposed ina display area DA, which will be described in detail with reference toFIGS. 1 to 3.

Referring to FIGS. 1 to 3, a gate line 121 and a storage electrode line131 are formed on a substrate 110. The substrate 110 may be formed oftransparent glass, plastic, or the like. The gate line 121 includes agate electrode 124. The storage electrode line 131 transfers apredetermined voltage (such as a common voltage Vcom), and extends in asubstantially horizontal direction. The storage electrode line 131 alsoincludes a pair of vertical portions 135 a extending substantiallyperpendicular to the gate line 121, and a pair of horizontal portions135 b connecting the ends of the vertical portions 135 a. The verticaland horizontal portions 135 a and 135 b of the storage electrode line131 are formed surrounding a pixel electrode 191.

A gate insulating layer 140 is formed on the gate line 121 and thestorage electrode line 131. Semiconductor layers (151 and 154) and dataconductors (171, 173, and 175) are formed on the gate insulating layer140. Referring to FIG. 3, a semiconductor layer 151 is formed on thegate insulating layer 140, and a data line 171 is formed on thesemiconductor layer 151. Referring to FIG. 2, a semiconductor layer 154is formed on the gate insulating layer 140, and a source electrode 173and a drain electrode 175 are formed on the semiconductor layer 154. Thedata line 171 is connected to the source electrode 173.

In some embodiments, a plurality of ohmic contacts (not shown) may beformed on the respective semiconductor layers 151 and 154, and betweenthe data line 171 and the source/drain electrodes 173 and 175.

The gate electrode 124, the source electrode 173, and the drainelectrode 175, together with the semiconductor layer 154, collectivelyconstitute a thin film transistor Q. A channel of the thin filmtransistor Q is formed in a portion of the semiconductor layer 154between the source electrode 173 and the drain electrode 175.

A first interlayer insulating layer 180 a is formed on the dataconductors 171, 173, and 175, and on an exposed portion of thesemiconductor layer 154. The first interlayer insulating layer 180 a mayinclude an inorganic insulator (such as silicon nitride (SiNx) orsilicon oxide (SiOx)) or an organic insulator.

A color filter 230 and a plurality of light blocking members are formedon the first interlayer insulating layer 180 a. The plurality of lightblocking members include a horizontal light blocking member 220 a and avertical light blocking member 220 b.

The light blocking members 220 a and 220 b are formed in a latticestructure of the color filter 230. The lattice structure includesopenings corresponding to an area for displaying images. The lightblocking members 220 a and 220 b are formed of an opaque material (thatdoes not transmit light). The light blocking members 220 a and 220 b areformed in the openings of the color filter 230. In particular, thehorizontal light blocking member 220 a is formed in a direction parallelto the gate line 121, and the vertical light blocking member 220 b isformed in a direction parallel to the data line 171.

The color filter 230 may display one of the primary colors (such as thethree primary colors red, green, and blue). However, the color filter230 need not be limited to the three primary colors red, green, andblue. In some embodiments, the color filter 230 may display one of cyan,magenta, yellow, and white-based colors. The color filter 230 may beformed of a material capable of displaying a different color for everyadjacent pixel.

A second interlayer insulating layer 180 b is formed on the color filter230 and the light blocking members 220 a and 220 b, covering the colorfilter 230 and the light blocking members 220 a and 220 b. The secondinterlayer insulating layer 180 b may include an inorganic insulator(such as silicon nitride (SiNx) or silicon oxide (SiOx)) or an organicinsulator. As shown in FIG. 2, a step is created due to a thicknessdifference between the color filter 230 and the light blocking members220 a and 220 b. Nevertheless, the effect of the step on surfaceplanarity can be mitigated by forming the second interlayer insulatinglayer 180 b over the step.

A contact hole 185 exposing the drain electrode 175 is formed in thecolor filter 230, the light blocking members 220 a, and the interlayerinsulating layers 180 a and 180 b.

The pixel electrode 191 is formed on the second interlayer insulatinglayer 180 b.

The pixel electrode 191 may be formed having a quadrangle shape. Thepixel electrode 191 includes a plurality of horizontal stems 192 a and194 a, and a plurality of vertical stems 192 b and 194 b crossing thehorizontal stems 192 a and 194 a. Further, the pixel electrode 192 isdivided into four subregions by the horizontal stems 192 a and 194 a andthe vertical stems 192 b and 194 b, and each subregion includes aplurality of minute branches 192 c and 194 c. In some embodiments, thepixel electrode 191 may further include an outer stem surrounding thepixel electrode 191.

The minute branches 192 c of the pixel electrode 191 form an angle ofapproximately 40° to 45° with the gate line 121 or the horizontal stem192 a. Also, the minute branches of two adjacent subregions may beperpendicular to each other. Furthermore, a distance between the minutebranches 192 c and 194 c may vary with an increase in a linewidth of theminute branches.

The pixel electrode 191 includes an extension 197 connected at lowerends of the vertical stems 192 b and 194 b. The extension 197 has alarger area than the vertical stems 192 b and 194 b. The pixel electrode191 is physically and electrically connected with the drain electrode175 through the contact hole 185 at the extension 197, so as to receivea data voltage from the drain electrode 175.

In some embodiments, the pixel electrode 191 includes a transparentelectrode 192 and a reflective electrode 194 disposed on a portion ofthe transparent electrode 192. Accordingly, a transflective liquidcrystal display is formed, comprising a reflective area RA and atransmissive area TA formed on the substrate 110.

In the reflective area RA, the pixel electrode 191 includes thetransparent electrode 192 and the reflective electrode 194 disposed onthe portion of the transparent electrode 192. In the transmissive areaTA, the transparent electrode 192 may be formed as the pixel electrode191. The transparent electrode 192 may be formed of a transparentconductive material (such as ITO or IZO), and the reflective electrode194 may be formed of a reflective metal (such as aluminum, silver,chromium, or an alloy thereof). In some embodiments (not illustrated),the reflective electrode 194 may have a dual-layer structure including alow-resistive reflective upper layer and a lower layer. Thelow-resistive reflective upper layer may be formed of aluminum, silver,or an alloy thereof. The lower layer may be formed of a material havingexcellent contact characteristics with ITO or IZO (such asmolybdenum-based metals, chromium, tantalum, or titanium).

Although not illustrated in the figures, an upper surface of the secondinterlayer insulating layer 180 b disposed at the portion correspondingto the reflective area RA may have a curved surface. Also, thetransparent electrode 192 and the reflective electrode 194 disposed onthe second interlayer insulating layer 180 b may be curved along theupper surface of the second interlayer insulating layer 180 b.

In the transmissive area TA, light that is incident from a rear side ofthe substrate 110 passes through liquid crystal molecules 310 of amicrocavity 305, and is then emitted to a front side (towards a cappinglayer 390), thereby displaying an image. In the reflective area RA,external light that is input from the front side enters into themicrocavity 305 and is reflected by the reflective electrode 194. Thereflected light then passes through the liquid crystal molecules 310 ofthe microcavity 305 again and is emitted to the front side, therebydisplaying the image. In this case, the curved surface of the reflectiveelectrode 194 induces diffused reflection of light, so as to prevent aphenomenon in which an object is reflected on the screen.

In some embodiments, the reflective area RA and the transmissive area TAmay each include one or more unit pixel areas. Referring to FIGS. 1 and4, the transmissive area TA may include a unit pixel area disposed on anupper left quadrant and a unit pixel area disposed on a lower rightquadrant diagonal to the upper left quadrant. The reflective area RA mayinclude a unit pixel area disposed on a lower left quadrant and a unitpixel area disposed on an upper right quadrant diagonal to the lowerleft quadrant. Although FIGS. 1 and 4 illustrate 2×2 pixel areas, itshould be understood that the layout of the reflective area RA and thetransmissive area TA described above (i.e. the 2×2 pixel areas) may berepeated across the entire pixel areas.

Furthermore, the thin film transistor Q and the pixel electrode 191described above are merely exemplary. In some embodiments, a structureof the thin film transistor Q and a design of the pixel electrode 191may be modified to improve side visibility.

A lower alignment layer 11 is formed on the pixel electrode 191. Thelower alignment layer 11 may correspond to a vertical alignment layer.The lower alignment layer 11 serves as a liquid crystal alignment layer,and may be formed of materials such as polyamic acid, polysiloxane,polyimide, or the like.

An upper alignment layer 21 is disposed at a portion facing the loweralignment layer 11, and the microcavity 305 is formed between the loweralignment layer 11 and the upper alignment layer 21. A liquid crystalmaterial including the liquid crystal molecules 310 is injected into themicrocavity 305 through a liquid crystal injection hole 307. Themicrocavity 305 may be formed in a column direction, that is, a verticaldirection of the pixel electrode 191. In some embodiments, the alignmentmaterial (for forming the alignment layers 11 and 21) and the liquidcrystal material (including the liquid crystal molecules 310) may beinjected into the microcavity 305 via capillary force.

In some embodiments, a height of a first cell gap in the reflective areaRA may be different from a height of a second cell gap in thetransmissive area TA. For example, the first cell gap may correspond toa first height d1 of the microcavity 305 in the reflective area RA, thesecond cell gap may correspond to a second height d2 of the microcavity305 in the transmissive area TA, and the first cell gap may be smallerthan the second cell gap such that dl is less than d2.

In some embodiments, the reflective area RA may be designed for λ/4wavelengths and the transmissive area TA may be designed for λ/2wavelengths, so as to equalize the polarization states of light reachinga last polarizer in the reflective area RA and the transmissive area TA.Specifically, the reflective area RA and the transmissive area TA may bedesigned for λ/4 and λ/2 wavelengths, respectively, by setting theheight of the first cell gap of the reflective area RA (d1) to be ½ ofthe height of the second cell gap of the transmissive area TA (d2).

The microcavity 305 is divided in a vertical direction by a plurality ofliquid crystal injection hole formation regions 307FP disposed at theportion overlapping with the gate line 121. As such, a plurality ofmicrocavities 305 are formed in a direction in which the gate line 121extends. Each of the microcavities 305 may correspond to one or two ormore pixel areas, and the pixel areas may correspond to the area fordisplaying an image.

A common electrode 270 and a lower insulating layer 350 are disposed onthe upper alignment layer 21. The common electrode 270 receives a commonvoltage and generates an electric field together with the pixelelectrode 191 (to which the data voltage is applied). The electric fielddetermines the tilt directions of the liquid crystal molecules 310disposed in the microcavity 305 between the two electrodes 270 and 191.The common electrode 270 and the pixel electrode 191 collectively form acapacitor to maintain the applied voltage even after the thin filmtransistor is turned off. The lower insulating layer 350 may be formedof silicon nitride (SiNx) or silicon oxide (SiO2).

In some embodiments, the common electrode 270 is formed on themicrocavity 305. In some other embodiments, the common electrode 270 maybe formed below the microcavity 305 and thus the liquid crystal may bedriven according to an in-plane switching mode.

A roof layer 360 is disposed on the lower insulating layer 350. The rooflayer 360 serves to support the microcavity 305. As previouslydescribed, the microcavity 305 is formed as a space between the pixelelectrode 191 and the common electrode 270. The roof layer 360 may beformed of a photoresist or other organic materials. In some embodiments,a thickness of the roof layer 360 may vary according to the cell gaps ofthe reflective area RA and the transmissive area TA. For example, athickness of a portion of the roof layer 360 corresponding to thereflective area RA (having a small cell gap) may be greater than athickness of another portion of the roof layer 360 corresponding to thetransmissive area TA (having a large cell gap).

An upper insulating layer 370 is disposed on the roof layer 360. Theupper insulating layer 370 may contact an upper surface of the rooflayer 360. The upper insulating layer 370 may be formed of siliconnitride (SiNx) or silicon oxide (SiO2).

In some embodiments, the capping layer 390 is disposed in the liquidcrystal injection hole formation region 307FP covering the liquidcrystal injection hole 307 of the microcavity 305. The capping layer 390may include an organic material or an inorganic material.

In some embodiments (for example, as illustrated in FIG. 3), a partitionwall formation portion PWP is disposed between microcavities 305adjacent to each other in a horizontal direction. The partition wallformation portion PWP may extend in a same direction as the data line171, and may be covered by the roof layer 360. The lower insulatinglayer 350, the common electrode 270, the upper insulating layer 370, andthe roof layer 360 are disposed in the partition wall formation portionPWP. The partition wall formation portion PWP serves as a partition wallstructure to partition or define the microcavity 305. In someembodiments, a partition wall structure (such as the partition wallformation portion PWP) between the microcavities 305 may allow theliquid crystal display to be more flexible. Accordingly, in thoseembodiments, the heights of the cell gaps can be more uniformlymaintained, and the stress generated in the display is small even whenthe substrate 110 is bent.

FIG. 5 is a plan view illustrating an exemplary embodiment in which thelayout of the reflective area and the transmissive area in FIG. 4 ismodified.

Referring to FIG. 5, the reflective area RA or transmissive area TA maybe disposed along a direction in which the gate line 121 extends, andthe reflective area RA and the transmissive area TA may be alternatelydisposed along a direction in which the data line 171 extends.

FIG. 6 is a plan view illustrating another exemplary embodiment in whichthe layout of the reflective area and the transmissive area in FIG. 4 ismodified.

Referring to FIG. 6, the reflective area RA or transmissive area TA maybe disposed along a direction in which the data line 171 extends, andthe reflective area RA and the transmissive area TA may be alternatelydisposed along a direction in which the gate line 121 extends.

Next, a method of manufacturing a liquid crystal display according to anexemplary embodiment of the inventive concept will be described withreference to FIGS. 7 to 17. Specifically, FIGS. 7, 9, 11, 13, 14, and 16depict cross-sectional views of the liquid crystal display of FIG. 1taken along line II-II, and FIGS. 8, 10, 12, 15, and 17 depictcross-sectional views of the liquid crystal display of FIG. 1 takenalong line at different stages of manufacturing.

Referring to FIGS. 1, 7, and 8, the gate line 121 is formed extending ina horizontal direction on the substrate 110, the gate insulating layer140 is formed on the gate line 121, the semiconductor layers 151 and 154are formed on the gate insulating layer 140, and the source electrode173 and the drain electrode 175 are formed on the semiconductor layer154. The data line 171 is formed on the semiconductor layer 151, and isconnected to the source electrode 173. Also, the data line 171 may beformed crossing the gate line 121 and extending in a vertical direction.

Next, the first interlayer insulating layer 180 a is formed on the dataconductors (source electrode 173, drain electrode 175, and data line171) and on the exposed portion of the semiconductor layer 154.

Next, the color filter 230 is formed on the first interlayer insulatinglayer 180 a at a position corresponding to the pixel area. The lightblocking members 220 a and 220 b are formed in the openings between thecolor filters 230.

Next, the second interlayer insulating layer 180 b is formed on thecolor filter 230 and the light blocking members 220 a and 220 b,covering the color filter 230 and the light blocking members 220 a and220 b. The contact hole 185 is formed in the second interlayerinsulating layer 180 b, and allows the pixel electrode 191 to beelectrically and physically connected to the drain electrode 175. Theupper surface of the second interlayer insulating layer 180 b disposedat a portion of the reflective area RA may be formed having a curvedsurface (not shown).

Next, the pixel electrode 191 is formed on the second interlayerinsulating layer 180 b.

In the reflective area RA, the pixel electrode 191 includes thetransparent electrode 192 and the reflective electrode 194 disposed on aportion of the transparent electrode 192. In the transmissive area TA,the pixel electrode 191 is formed as the transparent electrode 192.

Next, a sacrificial layer 300 is formed on the pixel electrode 191. Asillustrated in FIG. 8, an open portion OPN is formed in the sacrificiallayer 300. The open portion OPN is formed in a direction parallel to thedata line 171. Next, as illustrated in FIG. 10, the common electrode270, the lower insulating layer 350, the roof layer 360, and the upperinsulating layer 370 are formed in the open portion OPN so as to formthe partition wall formation portion PWP.

In some embodiments, the sacrificial layer 300 is formed havingdifferent thicknesses in the reflective area RA and the transmissivearea TA. To form the sacrificial layer 300 having different thicknesses,a slit mask or a halftone mask may be used.

Referring to FIGS. 9 and 10, the common electrode 270, the lowerinsulating layer 350, and the roof layer 360 are sequentially formed onthe sacrificial layer 300. The roof layer 360 may be removed in a regioncorresponding to the horizontal light blocking member 220 a disposedbetween adjacent pixel areas in the vertical direction using aphotolithography process. As a result, a portion of the lower insulatinglayer 350 corresponding to the horizontal light blocking member 220 a isexposed by the opening in the roof layer 360. As previously described,the common electrode 270, the lower insulating layer 350, and the rooflayer 360 are formed in the open portion OPN of the vertical lightblocking member 220 b, so as to form the partition wall formationportion PWP.

The roof layer 360 has a substantially greater thickness than the commonelectrode 270 or the lower insulating layer 350. An interlayer step isthus created between the reflective area RA and the transmissive area TAdue to the sacrificial layer 300 having different thicknesses. As aresult, the thickness of the roof layer 360 in the reflective area RAmay be greater than the thickness of the roof layer 360 in thetransmissive area TA (as illustrated in FIG. 9).

Referring to FIGS. 11 and 12, the upper insulating layer 370 is formedcovering the roof layer 360 and the exposed portion of the lowerinsulating layer 350.

Referring to FIG. 13, the upper insulating layer 370, the lowerinsulating layer 350, and the common electrode 270 are partially removedby dry-etching the upper insulating layer 370, the lower insulatinglayer 350, and the common electrode 270 to form the liquid crystalinjection hole formation region 307FP. In this case, the upperinsulating layer 370 may have a structure covering the side of the rooflayer 360, but is not limited thereto. For example, in some otherembodiments, the upper insulating layer 370 covering the side of theroof layer 360 may be removed to expose the side of the roof layer 360.

Referring to FIGS. 14 and 15, the sacrificial layer 300 is removed fromthe liquid crystal injection hole formation region 307FP by an oxygen(O2) ashing process or a wet-etching method, thereby forming themicrocavity 305 with the liquid crystal injection hole 307. Themicrocavity 305 is an empty space that is formed when the sacrificiallayer 300 is removed.

Referring to FIGS. 16 and 17, the alignment layers 11 and 21 are formedon the pixel electrode 191 and the common electrode 270 by injecting thealigning material through the liquid crystal injection hole 307. Thealigning material includes a solid and a solvent. Thereafter, a bakeprocess is performed so as to drive the solvent from the aligningmaterial.

Next, the liquid crystal material including the liquid crystal molecules310 is injected into the microcavity 305 through the liquid crystalinjection hole 307 using an inkjet method and the like.

Thereafter, the capping layer 390 is formed on the upper insulatinglayer 370 to cover the liquid crystal injection hole 307 and the liquidcrystal injection hole formation region 307FP, thus forming the liquidcrystal display illustrated in FIGS. 2 and 3.

While this inventive concept has been described in connection with whatis presently considered to be practical exemplary embodiments, it is tobe understood that the inventive concept is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A method of manufacturing a liquid crystaldisplay, comprising: forming a thin film transistor on a substrate;forming a pixel electrode, wherein the pixel electrode is connected to aterminal of the thin film transistor; forming a sacrificial layer on thepixel electrode, wherein the sacrificial layer includes a first portionhaving a first thickness and a second portion having a second thickness;forming a roof layer on the sacrificial layer; forming, by removing thesacrificial layer, a plurality of microcavities having a liquid crystalinjection hole; and injecting an alignment material and a liquid crystalmaterial into the plurality of microcavities through the liquid crystalinjection hole, wherein the first portion of the sacrificial layercorresponds to a reflective area, and the second portion of thesacrificial layer corresponds to a transmissive area.
 2. The method ofclaim 1, wherein the first thickness corresponds to a cell gap of thereflective area, and the second thickness corresponds to a cell gap ofthe transmissive area.
 3. The method of claim 2, wherein a thickness ofthe roof layer in the reflective area is greater than a thickness of theroof layer in the transmissive area.
 4. The method of claim 3, whereinforming the sacrificial layer on the pixel electrode further comprises:forming the first portion and the second portion alternately in adirection of a gate line connected to the thin film transistor.
 5. Themethod of claim 3, wherein forming the sacrificial layer on the pixelelectrode further comprises: forming the first portion and the secondportion alternately in a direction of a data line connected to the thinfilm transistor.
 6. The method of claim 3, further comprising: forming acommon electrode and a lower insulating layer on the sacrificial layerbefore forming the roof layer.
 7. The method of claim 6, furthercomprising: forming a capping layer on the roof layer to cover theliquid crystal injection hole.
 8. The method of claim 7, wherein: aliquid crystal injection hole formation region is formed between theplurality of microcavities, and the capping layer is formed covering theliquid crystal injection hole formation region.